The present invention relates generally to an image sensor packaging method and structure thereof, and more particularly to an image sensor packaging method that fabricates first a transparent layer of the image sensor, and then combines the image sensor with a microchip. The image sensor is thus automatically fabricated, thereby preventing the damage or waste of microchips and lowering the manufacturing cost and thickness of the image sensor. When cutting or carving the transparent layer, the amount of fragmental pieces generated is reduced, thus improving the conventional method for manufacturing image sensors.
In recent years, the prosperity of multimedia industry has made a trend of digitizing image data. The development of digital cameras, digital video cameras, image scanners, etc. represents that the age of digital images has arrived. The key component of the products listed above is an image sensor, which is one kind of electro-optical device in the electro-optical industry. The grand integration of video, audio, and digital communications in different platforms has sketched a new shape of people's life along the development of the computer network technology. Therefore, many different products that can exchange image data and information, such as personal computer, personal digital assistant, handheld personal computer, cellular phone, interactive television, web machine, facsimile machine, etc., have been developed.
In general, the image sensor is classified into three different categories, namely, the charge coupling device (CCD) image sensor, the complementary metal oxide semiconductor (CMOS) image sensor, and the contact image sensor (CIS). In practice, since the CIS does not constitute the optical focusing problem of the CCD image sensor, it is often used in a facsimile machine and an image scanner. Thus, the CIS will replace the CCD image sensor to become a standard image sensor used in intermediate or lower level scanners.
However, the quality of the image sensors described above depends mainly on the manufacturing processes and the costs. For example, in the U.S. Pat. No. 6,285,064, which is entitled “Chip Scale Packaging for Optical Image Sensor Integrated Circuits”, a manufacturing process is disclosed. In the manufacturing process, a plurality of micro lenses is applied onto a wafer. The wafer includes a plurality of image sensor integrated circuits. The micro lenses are applied to a sensing array portion of the image sensor integrated circuits. Then, an adhesive matrix is applied on the wafer. The adhesive matrix includes a plurality of openings located to correspond to the sensing array portion when the adhesive matrix is applied to the wafer. Next, a cover glass is applied on the adhesive matrix such that a cavity containing a non-adhesive material is formed over the micro lenses. One advantage of the image sensor packaging method is in that the distortion and decay of the received images can be reduced. However, after applying the cover glass, one still needs to planarize and cut the wafers. This will damage the wafer or increase the damage rate. In addition, cutting the cover glass will leave many glass particles on the image sensor. Therefore, defective products are easily derived from the manufacturing processes. Moreover, the manufacturing cost is relatively higher, too.